A smoke exhaust device of the above-described type is shown in the description "Turm und Bewaffnung Kampfpanzer Leopard A4" [Gun Turret and Armament of the Leopard A4 Combat Tank], June 1974, pp. 55 and 56.
These smoke exhaust devices are used to keep the combat space practically free from gunpowder gases during firing. During firing, part of the high-pressure gases enters the smoke exhaust device through the bores directed obliquely upward in the gun barrel. When a shell has left the gun barrel, the gas collected in the smoke exhaust device flows again out of the bores at a relatively high velocity and also entrains the gases located in the rear part of the gun barrel in the direction of the muzzle.
However, practice has shown that especially in the case of gun barrels of relatively small caliber, the function of this prior-art smoke exhaust device is not sufficient to reduce the CO value in the combat space greatly enough to rule out injury to the persons in the combat space.